Unexpected cell wall alteration-mediated bactericidal activity of the antifungal caspofungin against vancomycin-resistant Enterococcus faecium.

Unexpected cell wall alteration-mediated bactericidal activity of the antifungal caspofungin against vancomycin-resistant Enterococcus faecium. Antimicrob Agents Chemother. 2020 Aug 10;: Authors: Isnard C, Hernandez SB, Guérin F, Joalland F, Goux D, Gravey F, Auzou M, Enot D, Meignen P, Giard JC, Cava F, Cattoir V Abstract Enterococcus faecium has become a major opportunistic pathogen with the emergence of vancomycin-resistant enterococci (VRE). As part of the gut microbiota, they have to cope with numerous stresses including effects of antibiotics and other xenobiotics, especially in patients hospitalized in intensive care units (ICUs) who receive many medications. The aim of this study was to investigate the impact of the most prescribed xenobiotics for ICU patients on fitness, pathogenicity and antimicrobial resistance of the vanB-positive E. faecium Aus0004 reference strain. Several phenotypic analyses were carried out and we observed that caspofungin, an antifungal agent belonging to the echinocandins family, had an important effect on E. faecium growth in vitro. We confirmed this effect by electron microscopy and peptidoglycan analysis and showed that, even at a subinhibitory concentration (¼ × MIC, 8 mg/L), caspofungin had an impact on cell wall organization especially in abundance of some muropeptide precursors. By RNA-seq, it was also shown that around 20% of the transcriptome were altered in the presence of caspofungin w...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research